1. Field of the Invention
The present invention relates to a temporary clamp mechanism in a cable reel mounted on a steering apparatus of vehicles. The present invention also relates to a temporary clamp mechanism that eliminates the need to provide a steering wheel with a pullout clamp hole under the condition where a rotor of a cable reel is fastened to a steering column with the cable reel temporarily clamped to a stator through a rotation clamping member and the rotation clamping member, which has temporarily stopped the rotation of a rotor, are pulled out after assembling a steering wheel over the stator and rotor.
2. Description of Background Information
A known temporary rotation clamping mechanism for a cable reel is shown in FIG. 6 from, for example, Japanese Unexamined Patent Publication No.2000-48925. The cable reel 51 is mounted on a steering apparatus of a vehicle for electrically connecting circuits of a vehicle body with electrical devices (a horn switch, an air bag, etc.) A stator 52 fastened to a steering column and a rotor 53 fastened to a steering wheel (hereafter abbreviated as a wheel) side are constructed so that they relatively rotate. In the annular hollow space 54 formed by the stator 52 and the rotor 53, a flat cable 55 is housed in a wound condition and the flat cable 55 is wound up of wound out in accordance with the direction of rotation of the rotor 53 which follows the wheel rotation.
In mounting the aforementioned cable reel 51 on the steering apparatus, the stator 52 and the rotor 53 are positioned in a predetermined rotation phase, and side, generally T-shaped, rotation clamping members 56 are temporarily placed over the stator 52 and the rotor 53 from an upper position so that the stator 52 and the rotor 53 cannot rotate in order to maintain the predetermined rotation phase. That is, a lateral piece 57 of the rotation clamping member 56 is fixed to an upper surface 53a of the rotor 53 through a clamp hole 57a, and a bottom portion 58a of a vertical piece 58 is fixed in the recess 59a of a stop 59 on the peripheral surface of the stator, preventing rotation of the stator and the rotor.
The aforementioned cable reel 51 is fastened to a steering column under the condition of the rotor 53 connected with the stator by the rotation clamping member 56, and subsequently, the steering wheel 60 is assembled on top. After mounting the steering wheel 60 (note FIG. 7), the rotation clamping member 56 is removed to enable the rotor 53 to rotate. That is, as shown in FIG. 7, the wheel hub 61 of the steering wheel 60 is provided with a clamp hole 61a for removing the rotation clamping member 56. In order to effect removal of the rotation clamping member, an operator holds and pulls up the top portion 58b of the vertical piece 58 of the rotation clamping member 56 through the clamp hole 61a. 
However, with the temporary rotation clamping construction in the cable reel 51, the clamp hole 61a cannot be machined through the wheel hub of the steering wheel 60, the rotation clamping member 56 must be extracted laterally, and it is difficult to laterally remove the rotation clamping member because of a narrow working space. In addition, when the clamp hole 61a is provided through the wheel hub of the wheel 60, there are problems such as decrease in strength of the wheel 60, and the like.
The present invention has been made considering the aforementioned problems, and makes it possible to remove the rotation clamping member, not by removing it laterally, but by pulling it upwardly without providing the wheel hub of the steering wheel with a clamp hole.
In order to solve the aforementioned problems, the present invention offers a temporary rotation clamping mechanism for a cable reel, the cable reel being mountable on a steering apparatus and includes a rotor and stator. The rotor is temporarily clamped to the stator through rotation clamping members. The rotation clamping members include a vertical piece positionable in an axial direction of the cable reel and a lateral piece horizontally projecting toward the center of the cable reel from a middle position of the vertical piece, and a lateral piece is connected with the vertical piece through a hinge which is pivotable downwardly. A bottom portion of the vertical piece is inserted into an engaging area provided on an outer peripheral surface of the stator and the lateral piece projects over an upper surface of the rotor. A projection on the upper surface of the rotor is inserted into an engaging clamp hole provided in the lateral piece to temporarily stop rotation of the rotor.
When releasing the rotation clamping, the lateral piece and the rotor are disengaged by holding and pulling up an upper portion of the vertical piece to allow the lateral piece to be lifted up through the outside of the wheel boss by engagement against a periphery of a wheel hub followed by downward pivoting of the hinge, so that the rotation clamping members may be removed.
In another aspect of the temporary rotation clamping mechanism in a cable reel of the present invention, the rotation clamping members temporarily placed over the stator and the rotor have a construction where the lateral piece is connected through the hinge which permits the lateral piece to pivot downwardly from the level of the root. Therefore, the lateral piece of the rotation clamping members may be lifted up to release the clamped rotation of the rotor and the stator which engages the periphery of the wheel hub to pivot downwardly from the level of the root and passes through the outer surface of the wheel hub to be removed smoothly upwardly. As a result, even if a removal clamp hole is not provided through the wheel hub, the rotation clamping members can be quickly removed by turning aside the wheel hub smartly.
In a further aspect of the present invention, the hinge is formed unitarily and in one piece to include a lateral piece with a thin neck portion, and the lateral piece and the vertical piece are formed unitarily and in one piece through the hinge. The rotation clamping members may be formed of any suitable resin, and the vertical piece and the lateral piece are connected through the hinge. It is also possible that the vertical piece and the lateral piece are formed separately and integrated into a unit by engagement.